Generational dependency and elderly care : a psychological interpretation of cultural norms and exchange

ln spite of the complexity of such dynamic relationships in the caregiving system, the literature shows that dominant research paradigm has places elderly care in the framework of a simple, unqualified social exchange theory. The primary goal of this paper to critique research approach based on the social exchange theory. First, we wish to discuss how the exchange theory lies at the heart of the debate between the proponents and opponents of having family members as the primary care providers for elderly. We wish to review the basic assumptions that social exchange theory holds about caregiving relationships. Second, we suggest that focusing on the perceptions and expectations between the elderly person and his/her caretaker may instead be a more valuable approach to understanding the caregiving relationship. Here we submit that an example of the perception-expectation approach is reflected in the “secondary baby talk” between caregiver and the elderly. Third, we wish to discuss how such an approach may provide insight into a range of culturally variant behaviors for family members who are caring for elderly

Convergence of subdivision schemes and smoothness of limit functions

AbstractStarting with vector λ=(λ(k))k∈Z∈ℓp(Z), the subdivision scheme generates a sequence {Sanλ}n=1∞ of vectors by the subdivision operator Saλ(k)=∑j∈Zλ(j)a(k−2j),k∈Z. Subdivision schemes play an important role in computer graphics and wavelet analysis. It is very interesting to understand under what conditions the sequence {Sanλ}n=1∞ converges to a Lp-function in an appropriate sense. This problem has been studied extensively.In this paper, we consider the convergence of subdivision scheme in Sobolev spaces with the tool of joint spectral radius. Firstly, the conditions under which the sequence {Sanλ}n=1∞ converges to a Wpk-function in an appropriate sense are given. Then, we show that the subdivision scheme converges for any initial vector in Wpk(R) provided that it does for one nonzero vector in that space. Moreover, if the shifts of the refinable function are stable, the smoothness of the limit function corresponding to the vector λ is also independent of λ, where the smoothness of a given function is measured by the generalized Lipschitz space

Expression profiling of ascorbic acid–related transporters in human and mouse eyes

PURPOSE: Ascorbic acid (AsA) is an important antioxidant in the eye. Ascorbic acid is usually transported by sodium-dependent AsA transporters (SVCTs), and dehydroascorbic acid (DHA) by glucose transporters (GLUTs). This study investigates these AsA-related transporters in human compared with mouse eyes. METHODS: Five pairs of human donor eyes and 15 pairs of mouse eyes were collected. Immunofluorescence and in situ hybridization were performed to detect SVCTs and GLUTs expression in the ciliary epithelium, retina, and lens epithelial cells (LECs). These tissues were isolated with laser microdissection followed by extraction of total RNA. Quantitative PCR (qPCR) was performed to examine the mRNA level of SVCTs and GLUTs in human and mouse ocular tissues. RESULTS: Immunofluorescence and in situ hybridization showed SVCT2 and GLUT1 expression in human ciliary epithelium with varied distributions. Sodium-dependent AsA transporter 2 is expressed only in the pigmented epithelium (PE), and GLUT1 is predominately expressed in the nonpigmented epithelium (NPE). However, SVCT2 was not identified in mouse ciliary epithelium, whereas GLUT1 expressed in both PE and NPE. Laser microdissection and qPCR revealed high levels of SVCT2 mRNA in human RPE cells and murine neural retina. Sodium-dependent AsA transporter 1 mRNA could be detected only in human and murine LECs. Glucose transporter 3 and GLUT4 mRNA could not be detected in either the human or mouse ciliary processes or in the lens epithelium. CONCLUSIONS: These fundamental findings indicate AsA transporter expression in eyes of humans is significantly different compared with mice. This may explain why human aqueous and vitreous humors contain higher AsA levels compared with other animals